System for heating conductors of the second class.



No. 663,929. Patented Dec. l8, 900. C. D. RA'AB.

SYSTEM FOR HEATING GONDUCTUBS OF THE SECOND CLASS.

(Application filed Apz-JSO, 1900.)

(No Model.)

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UNITED STATES CARL DANIEL RAAB, OF KAISERSLAUTERN, GERMANY.

SYSTEM FOR HEATING CONDUCTORS OF THE SECOND CLASS.

SPECIFICATION forming part of Letters Patent No. 663,929, dated December 18, 1900- Application filed April 30, 1900- To all whom it may concern:

Be it known that I, CARL DANIEL RAAB, a subject of the King of Prussia, German Emperor, residing at the city ofKaiserslantei-n, in the Kingdom of Bavaria, German Empire,

have invented certain new and useful Improvements in Methods of Heating Conductors of the Second Class, of which the following is a full, clear, and exact description.

The present invention relates to a method of heating conductors of the second class, which consists, essentially, in the insertion of conductors of the first class and conductors. of the second class between the separate wires I 5 and one or more heating resistances ina special wire in such a manner that the heating resistance after the incandescent body has become conducting is deprived of current by magnetic neutralization or that the current flowing through the heating resistance is reduced to a very small amount.

My new method is applicable to all ourrent-distribution systems supplied with alternating current in which magnetic neutralizing connections are possible.

The heating resistance can be of various kinds. For instance, it may consist of a thin platinum wire which is wound upon a mica disk placed close to the incandescent body.

In my new method of heating conductors of the second class I may either reduce the loss of energy by means of suitably-arranged cut-outs and controllers, or I may simplify the heating, or I may use the devices for heating simply as auxiliary means, which means can be again out out as soon as the heating has taken place.

In the accompanying drawings some constructional examples of the invention are illustrated.

Figure 1 shows an application of my new method of heating to a simple two-wire system. Fig. 2 illustrates the application to the simple three-wire system. Fig. 3 illustrates the application to a heating device for incandescent bodies operating by magnetic neutralization which can be inserted at any suitable points of the distribution system or also attached to another source of current. Fig. 4 illustrates the same arrangement for wire systems with mesh grouping, (A system.) Figs. 5 and 6 illustrate arrangements which Serial No. 14,971. (No modeladmit of the heating of incandescent bodies connected to the separate branches of multiple-wire systems by means of a single magnetic neutralization device. Figs. 7 and 8 illustrate the application of atension-divider in the two-wire system.

In Fig. 1 for the purpose of magnetic neutralization between the two branches of an alternate-current circuit the winding 1 is placed with the incandescent lamp 2 acting as a conductor of the first class and a second winding 3 with the incandescent body 4 in two parallel branch wires. The two windings 1 and 3 are adapted to induce equal but opposite fluxes in a common magnetic circuit provided with the secondary coil 6, containing the heating device 5. By this arrangement the heating resistance 6, which is at first only excited from the winding 1, becomes currentless as soon as the winding 3, owing to the incandescent body 4 becoming conducting, receives a current of such strength as to neutralize the action of the winding'l upon the winding 6.

Fig. 2 illustrates the application of the magnetic neutralization device for the three-wire system. Between the neutral wire and the one outer wire is placed the conductor of the first class, which may, for instance, be the incandescent lamp 7 with a coil 8, and between the neutral wire and the other outer wire is inserted an incandescent body 9 and another coil 10. The two coils 8 and 10 are adapted to produce equal but opposite fluxes in a common magnetic circuit, on which, moreover, is placed the secondary coil 12, connected to the heating resistance 11. The electric and magnetic conditions of the windings 8 and 10 are so arranged that the heating resistance 11 receives current as long as the incandescent body 9 is not conducting, but the heating resistance 11 becomes currentless when the incandescent body 9 has become conducting.

According to Fig. 3, the coils 13 and 14 are inserted in parallel and are adapted to produce opposite fluxes in a common magnetic circuit. With the winding 13 is inserted in series a condoctor of the first classor instance, the incandescent lamp 15-and with the winding 14: in like manner the incandescent body 16. Moreover, the incandescent bodies 17 and 18 are directly connected to the outer lines.

From the winding13 is branched ofi in the method set forth by Hicks a secondary-currentcircuit in which are placed the heating resistances 19 2O 21. The current which flows through the incandescent lamp 15 and winding 13 induces a secondary,current flowing through the heating-resistances 19 2O 21, by means of which the incandescent bodies 16 17 18 are heated and become conducting. Care must be taken that the incandescent bodies 17 and 18 becomeconducting at the same time as the incandescent body 16 or even somewhat sooner than 16.

Fig.4 illustrates the application of the aforesaid method of heating in the case of multiple-wire systems with mesh (A system) grouping. The current passes first through the incandescent lamp and the winding 13 and then induces the secondary current flowing through the heating resistances 19 2O 21, whereby the incandescent bodies16 17 18 are neated. After this heating it is possible, with aid of the heating device illustrated in Figs. 3 and 4, by the use of suitable connecting devices, to heat further incandescent bodies in the same manner as the bodies 17 and 18 are heated.

The heating device illustrated in. Fig. 3 is applicable in the same manner as in Fig. 4 to the simple three-Wire system also.

According to Fig. 5 the windings 22 and 23 producing opposite fluxes and. placed upon a common magnetic circuit are inserted in the two branches of a mesh grouping. The incandescent body 24 is inserted in series with the winding 22 and the incandescent body 25 with the winding 23.- A conductor of the first class-as, for'instance, the incandescent lamp 26 with a on t-out 27--is inserted in parallel to the incandescent body 24. From the winding 22 is branched off a secondary-current circuit of the Hicks type con taining the heating resistance 28 and from the winding 23 a similar circuit containing the heating-conductor 29. When the current passes, the cut-out 27 must be closed. The current then .fiows through the incandescent lamp 26 and the winding 22, causing theheating resistance 28 to become operative. When the incandescent body 25 becomes heated, the heating-conductor 28 loses its current. It, then, the incandescent lamp 26 is cut out, the heating-conductor 29 becomes operative, and consequently the incandescent body24 ismade conducting and the secondary current in the heating resistance 29 disappears.

Fig. 6 illustrates the application of the above-described heating method to the simple three-wire system; If a resi'stanceis to be inserted in series with the incandescent bodies, itis preferably not to-form a com- .plete iron magnetic circuit for the windings interpolated, which serve for the magnetic neutralization. Then there is magnetic leakage whereby-the incandescent bodies possess without further arrangement an inserted resistance, which acts inductively.

ilnthe method illustrated in Fi-g. 7 for the heating-of conductors of the second class a tension-divider is made use of. Thereby the two windings 30 and 31 are again connected on a common magnetic circuit. Between the two windings 30and31 are placed at both sides of the middle line 32 the windings 33 and 34 on a second common magneticcircuit. While the windings 30 and 31 producemagnetic fluxes in the same direction, the wind ings 33 and 34 produce opposed fluxes, so that they act as indu'ctionless resistancesas long as they are. equally loaded. The apparent fiuX of the windings 3O 31 33 34 is indicated in the diagram by means of the arrows 35, 36, 37, and 38. The incandescent bodies 39 and 40 are connected to the outerwires 41 and 42, and the heatingresistances 43 and 44 areconnected, onthe one hand, to the middle wire 32 and, on the other hand, to the terminals 45 and 46 of the windings 33 and 34. The incandescent lamp 47 is placed between the middle wire 32 and the outer wire,.41. When the cut-outs 48 49 50 are closed, there is at first present botha primary and a secondary current circuit. The primary current flows through the lamp 47. Consequently the windings 34 and 31 are less heavily loaded than the windings 33 and 30, so that in the heat ingresistance. 43 a secondary current is produced of the Hicks type. By means of the resistance 43 the incandescent body 39 then becomesconducting. As soon as the current strength in the incandescent body 39 has become equal to that of the incandescent lamp 47 the secondary current in the heating-resistance body 43 disappears, because the windings 33and 34 arenow equally loaded. After this. the cut-out 49 is openedrand then the cut-out 50 and the cut-out 51 are closed and then the cut-out 52. Consequently the heating resistance 44has a secondary current flowing through it, whereby the heating body 40 becomes conducting. As soon as the strength of the current in the incandescent body 40 has become equal to that of the incandescent body 39 no more secondary current flows through the resistance 44, because here again the windings 33and34 are equally loaded. Theheating resistance 44 can now be cutout.

In the connection above described the heating resistances 43 and 44 conduct primary current also. This current is, however, of very feeble strength, and may therefore be negleeted. The ohmic'resistance of the windings 43 and. 44 is considerably greater than that of the-windings 38 and 37.

The constructionalform illustrated in Fig. 8 distinguishes itself from that shown in Fig. 7 only inthatinstead of the 'Hicks system a Special secondary coil 53-is made useof. In other details the arrangementsand operation will be obvious withoutfurther explanation.

The applicability of the tension-divider, accordingto Fig. 7is not limited to the incandescent bodies 39 and 40. Other connections may also be made thereto without causing disturbances. For instance, the middle wire may be connected either to the point 45 or to the point 46, and the outer wires may be connected to the outer ends of the windings and 31. As the windings 33 and 34 are free from induction and possess only a very small ohmic resistance, the differences of potential between the middle wire and the outer wires will be very small.

In the method illustrated in Fig. 7 the whole of the incandescent bodies do not need to be inserted between the three wires 32, 41, and 42. It is even preferable instead thereof in the case of a larger number of incandescent bodies to provide several windings 33 34 each with a three-line branch system. The incandescent bodies are then inserted in the branches and suitably distributed.

If the incandescent lamp shown in the arrangements illustrated in Figs. 1 to 6 be replaced by an inductive winding, then this latter can be united with the winding lying in the same branch and serving for the magnetic neutralization device. In this case both windings are arranged to produce a flux in the same direction. then a larger number of windings than the other winding belonging to the magnetic neutralization device.

With the incandescent bodies illustrated in Figs. 1 to 6 there can also, of course, be other incandescent bodies inserted in parallel without thereby departing from the prin= ciple of my invention.

Having now described my invention, what I claim as new, and desire to secure by Letters Patent, is-

In a system for heating conductors of the second class, the combination of first and sec 0nd class conductors, a heater in the secondary of a transformer, diiferential primary coils for said transformer, alternate coils having in circuit with them a first and a second class conductor respectively.

In witness whereof I have hereunto set my hand in presence of two witnesses.

CARL DANIEL RAAB.

Witnesses ALoIs GOBANZ, OSCAR BocK.

Both together possess 

